The invention relates to an apparatus for preparing a mixture of an active agent and a diluting agent, comprising a container for receiving the diluting agent and a cartridge for receiving the active agent within an interior of the cartridge being de-limited by wall sections, the cartridge being adapted to be inserted into the container and being configured such that the active agent may be discharged into the container and diluted therein with the diluting agent, the cartridge, further, having a first wall section adapted to be at least partially disconnected from a surrounding second wall section, the first wall section being connected to a third wall section via an actuator, the third wall section being separated from the first wall section by the second wall section.
The invention, further, is related to a method for filling a cartridge for an apparatus for preparing a mixture of an active agent and a diluting agent, comprising a container for receiving the diluting agent and the cartridge for receiving the active agent within an interior of the cartridge being de-limited by wall sections, the cartridge being adapted to be inserted into the container and being configured such that the active agent may be discharged into the container and diluted therein with the diluting agent, the cartridge, further, having a first wall section adapted to be at least partially disconnected from a surrounding second wall section, the first wall section being connected to a third wall section via an actuator, the third wall section being separated from the first wall section by the second wall section.
An apparatus and a method of the afore-mentioned kind is known from DE-A1-35 35 986.
Apparatuses of the kind mentioned at the outset are used to dilute certain active agents, for example cleaning agents, insecticides, plant-protective agents or the like with an appropriate diluting agent, in particular water, and to distribute the mixture thus prepared, in particular by spraying or vaporizing. The active agent may be a liquid but may also be a powder or a granule.
In particular designs of such apparatuses, bottle-like containers are used having a bottleneck with an outer thread. The bottle-like containers are first filled with a predetermined amount of the diluting agent, for example water. A cartridge of the above-mentioned kind is then inserted into the bottleneck and, finally, a head of a spraying device is screwed thereon which typically also comprises a pump.
During the screwing-on of the head the cartridge is automatically opened so that the active agent from the interior of the cartridge is dispensed into the interior of the container. By agitating the container the active agent is mixed with the diluting agent. The mixture thus prepared may be sprayed by actuating the pump.
It goes without saying that the afore-mentioned design and application examples shall only be understood as an illustration and do not restrict the scope of the present invention.
In the apparatus according to DE-A1-35 35 986, mentioned at the outset, the embodiment described therein uses a cartridge of essentially cylindrical design. The cartridge comprises a hollow-cylindrical pot being open downwardly on one side and having an upper top plate with a circular through-opening. A piston rod is snugly guided through the through-opening and has a piston at its lower free end being simultaneously a closure for the otherwise open lower end of the cylindrical pot.
In a retracted position of the piston rod, the piston closes the pot downwardly so that a wholly enclosed interior of the pot is constituted being filled with an active agent in a first operational position of the cartridge.
For emptying the cartridge, the piston rod is displaced downwardly until the piston is moved out of the lower open end of the cylindrical pot so that an annular opening is created between the cylindrical surface of the pot and the piston rod. The active agent may be dispensed from the cartridge through this annular opening.
For filling the cartridge, the latter is positioned upside down so that the afore-mentioned piston is directed upwardly. By displacing the piston rod the above-mentioned annular opening may be established and the cartridge may be filled according to a predetermined quantity by means of an appropriate filling syringe, when a liquid active agent is used.
The prior art cartridge has the disadvantage that a sealing is required at two locations, namely at the passage of the piston rod and, further, at the outer periphery of the piston. This sealing must be established reliably because active agents sometimes are aggressive media which should not penetrate outwardly prior to their intended use. Further, the prior art cartridges require a complicated manufacture since they must be made with appropriate tight fits and because it is necessary during the assembly of the cartridge to fit the piston with its piston rod relative to the pot.
The prior method has the disadvantage that the cartridge must be filled via an annular opening which requires a complicated manipulation of a filling syringe. In particular, it presents a problem in this case to effect filling with a powder or with a granule.